Semiconductor and micromechanical dies or chips are frequently packaged for protection against an external environment. The package provides physical protection, stability, external connections, and in some cases, cooling to the die inside the packages. Typically the die is attached to a substrate and then a cover that attaches to the substrate is placed over the die. Alternatively, the die is attached to a cover and then a package substrate is formed on the die. As more devices are designed to provide wireless connectivity, packages are adapted to allow antennas to be connected to the one or more chips that are inside a package. The external antenna connections increase the assembly complexity and cost of producing a device.
Antennas are typically formed on the system board for the device or on a connected PCB (Printed Circuit Board). The connection to the chip package is made via the PCB. This is a long and complex connection through the PCB, and the package substrate to reach the chip. Impedances are difficult to control and there are reflections at the interfaces. While an antenna on a PCB is inexpensive, the quality of the antenna is limited. In some cases separate external antennas are used which are more expensive to produce and package and may have even more complex connection paths.
As the sizes of wireless devices are reduced, RF (Radio Frequency) packages are placed ever closer to digital and baseband packages. The digital and baseband packages typically generate noise and interference that can disrupt or impair the operation of the RF systems. The RF packages and the antennas typically generate noise and interference that can disrupt the operation of each other and of the digital and baseband packages. As a result, components are spaced apart and shielded by metal cases that cover chips inside packages. In some cases, a package may include internal shielding to avoid interference from the digital circuitry or RF components respectively. This further increases the size and complexity of a device.